Single Scroll Chaos . Shake phone to start.

253

03:13:10

What happens when you couple a good old Twin-T single NPN RC oscillator with a tweaked silicon  controlled rectifier ?  CHAOS !. This circuit has s very nice chaotic attractor with only one scroll. As usual, this is realized with only R,C and BJT's.
Shake to start.

published 9 years ago

emogenet

9 years ago

Theory of operation: the Twin-T RC oscillations have a slow voltage rise. When they reach the SCR's critical voltage, the SCR opens wide and brutally drains all the energy from the oscillator. It thens closes, and the osc. Res

emogenet

9 years ago

... restarts from a random point because the SCR has a built-in hysteresis.

emogenet

9 years ago

IRL : http://imgur.com/a/Fzrwn

nikisalli

9 years ago

Very nice specially the waveform on the xy oscilloscope that looks like a galaxy 👍

emogenet

9 years ago

Thx! And yeah, the real circuit has a really nice XY polt. Chaotic circuits are notoriously hard to represent nicely on a simulator (need to simulate a very long time to "fill up " the plot). Digital oscilloscopes also have a fairly hard time, but old analogue scope make beautiful pictures with chaotic circuits because they compute true physical integrals.

hurz

9 years ago

Cool, im your biggest fan! Like the way you do electronic and would like to see a scope Video ;-)

emogenet

9 years ago

OK, as per hurz, request, here's a bunch of vids :

emogenet

9 years ago

First, circuit on a digital storage scope. Bottom line : it sucks, even after trying to find the best possible sampling mode.

emogenet

9 years ago

https://youtu.be/7Xsbdisu20M

emogenet

9 years ago

Next, same thing on an analog scope:

emogenet

9 years ago

https://youtu.be/pwmjuu9xnyU

emogenet

9 years ago

Finally, a vid that shows what happens when you tweak the resistor in the SCR, showing various phases/modes of chaos, period doubling and tripling, etc ...

emogenet

9 years ago

https://youtu.be/uLnOj7pNy9g

hurz

9 years ago

Love all three videos! This is applied science. Start with an idea in simulation and then bring it in real to work!!! Awesome!

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